Fatty acid biodispersant and methods of use

ABSTRACT

Methods and compositions for dispersing a biofilm in an aqueous stream using fatty acids are disclosed. The fatty acids may have the formula: R 1 -R 5 —CH 3  wherein R 1  is an aryl or arylalkyl, —COR 2 , —COOR 2 , or —CONR 3 R 4 , —PO 3 (R 2 ) 3 ; R 2  is H, an alkyl, an aryl or arylalkyl, or a halide; R 3  and R 4  may be the same or different and are H, a hydroxyl, an alkyl, an aryl or arylalkyl, a halide, or a sulfo (sulfonic acid group); R 5  is an aliphatic chain having 2-30 carbon atoms and at least one double bond; and wherein when R 1  is —COOH and R 5  has eight carbon atoms and the FA has only one double bond, such double bond is not on the number 2 carbon.

FIELD OF THE INVENTION

Embodiments of the present invention relate to methods for reducingmicrobial biofilm on surfaces in contact with systems, including but notlimited to, aqueous systems. More particularly, the embodiments of thepresent invention relate to the use of an environmentally friendly fattyacid biodispersant for reducing microbial biofilm.

BACKGROUND OF THE INVENTION

Industrial processes or operating-water systems, such as open or closedwater-cycle systems, offer suitable conditions for the growth ofmicroorganisms. Industrial processes include, but are not limited to,oil and natural gas systems and their down-hole applications and coolingwater systems. Other examples of industrial systems are those systemsthat are found in the food and beverage industries. These water systemsmay form a harbor or reservoir that perpetuates growth of pathogenicmicroorganisms such as Legionella pneumophila, Pseudomonas aeruginosa,sulfate reducing bacteria, and other microbial fouling pathogens.

Many of these microorganisms form a slime known as biofilm on thesurfaces of water-bearing systems. The biofilms offer a selectiveadvantage to microorganisms to ensure the microorganisms' survival or toallow them a certain time to exist in a dormant state until suitablegrowth conditions arise. In the case of cooling water systems inparticular, these biofilm deposits can lead to reduced heat exchangeefficiency, pipeline damage, and corrosion within the systems. Adverseeffects on process control are possible, which can ultimately reduce theefficiency of the industrial process in question and impair productquality. In addition, biofilm or slime deposits generally lead to higherenergy consumption.

Control of biofilms involves the prevention of microbial attachment andthe removal of existing bio-films from surfaces. While removal in manycontexts is accomplished by short cleansing treatments with highlycaustic or oxidizing or non-oxidizing agents, the most commonly usedmaterials to control bio-films are biocides and biodispersants.

The deposition of the bacterial slimes may be controlled with biocidesthat kill off the microorganisms in the operating water and thus preventslime production. Due to the protective nature of biofilms, however,larger concentrations are needed to penetrate the biofilm and kill themicroorganisms within. Thus, biocides to control biofilm increase costs,and because of their toxicity, biocides pose considerable dangers tothose handling them and to the environment.

Surfactants are also regularly applied in water treatment programs asbiodispersant agents believed to play a role in the removal of organicmasses from surfaces. Surfactants may also enhance biocide efficacy orassist in the water miscibility of various biocidal agents.Unfortunately, some surfactants are toxic to non-target aquaticorganisms upon discharge to common receiving bodies of water or possessfunctional groups that have the potential to generate AOX species, suchas amines and amides, and are currently regulated in European countries.

The more non-toxic surfactants often require higher levels ofconcentrations to achieve their purpose, thereby making themuneconomical due to the huge amount of water treated, and prone toforming high levels of unwanted foam. Foaming results in the need tofeed antifoam compositions to the system. Foam, even with feedingantifoam compositions, may be problematic in some industrialapplications like air separation processes.

Additionally, in many aqueous systems, such as in industrial coolingsystems, scale control agents (“SCA”) are added to the system water toinhibit or control scale formation that would otherwise form. Such scaleforming precipitates include calcium, magnesium, and iron or coppersalts and complexes. In many cases in which biofilm control agents arealso added to these systems, the biofilm control agent impairs theability of the SCA to remain dissolved or suspended in the water system.Undesirable precipitation of the SCA means that less of the SCA isavailable in the system water to perform its intended scale controlfunction.

BRIEF DESCRIPTION OF THE INVENTION

It was surprisingly discovered that diffusible signal factors (“DSF”),such as fatty acids, were effective biodispersants in aqueous industrialprocesses. The fatty acid biodispersants are low-foaming and do notappear to impair the ability of the SCA to remain suspended in the watersystem. Accordingly, methods and compositions for dispersing a biofilmin an aqueous stream are disclosed.

In one embodiment, a method is disclosed for dispersing a biofilm in anaqueous stream by contacting the aqueous stream with a biodispersantcomposition with at least one unsaturated fatty acid which is not2-decenoic acid (“FA”) therein. The FA may be a fatty acid having apolar head group on a terminal end. The biodispersant compositionoptionally also comprises 2-decenoic acid.

In another embodiment, biodispersant compositions are disclosed. Thebiodispersant composition may have at least one unsaturated fatty acidwhich is not 2-decenoic acid (“FA”). The FA may have a polar head groupon a terminal end, and the biodispersant composition optionally alsocomprises 2-decenoic acid. The biodispersant composition may furtherinclude at least one emulsifier selected from ethoxylated surfactants,alkyl alcohols, carboxylic acids, and combinations thereof and maycomprise an emulsion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph showing the % Reduction results of various exemplaryand comparable biodispersant compositions on biofilms in artificialcooling-water.

FIG. 2 is a graph showing the % Reduction results of an exemplarybiodispersant composition at various concentrations and a comparativecomposition at 50 ppm on biofilms in artificial cooling-water.

DETAILED DESCRIPTION

Many species of bacteria use quorum sensing to coordinate multiple typesof behavior with other bacteria, including biofilm-forming or dispersingbehavior. In the quorum sensing process, molecules called diffusiblesignal factors (“DSF”), act as signals to communicate bacteria behaviorfrom cell-to-cell. It was surprisingly discovered that DSF includingfatty acids were effective biodispersants in aqueous industrialprocesses, such as cooling-water systems including cooling towers. Thefatty acid biodispersants are low-foaming and do not appear to impairthe ability of SCA to remain suspended in the water system. Withoutlimiting this disclosure to one theory of operation, it is believed thatfatty acids signal the bacteria colony to disperse the biofilm andreturn to the planktonic state or act as quorum quenchers by disruptingsignal communications. The long acid chain in fatty acids may alsopenetrate a biofilm and disperse it via micellar mechanisms.Accordingly, methods and compositions for dispersing a biofilm in anaqueous stream using fatty acids are disclosed. More particularly, thebiofilms are at least 1 μm thick, such as 1-3000 μm, 1-1000 μm, or10-900 μm. The biofilm may be formed by and contain bacteria. In anembodiment, the bacteria are Pseudomonas, Burkholderia, Areomonas,Pasteurella, Pantoea, Alcaligenes and Sphingomonas, as well as anaerobessuch as sulfate reducers (Desulfovibrio) and also Legionella.

An article titled A Fatty Acid Messenger Is Responsible for InducingDispersion in Microbial Biofilms, published in March 2009 in the Journalof Bacteriology (“Article”) is incorporated by reference herein in itsentirety. The Article discloses that cis-2-decenoic acid may be used todisperse biofilms. However, the Article states that the amount ofcis-2-decenoic acid which is needed for activity is 1.0 nM to 10 mM.However, testing has demonstrated that the actual amount needed isseveral times more than that for sufficient activity, making the use ofcis-2-decenoic acid impractical. Additionally, the Article disclosesthat cis-2-decenoic is specific in this respect and that eventrans-2-decenoic acid would not work the same since the amount oftrans-2-decenoic acid needed would be in the mM range, rather thanstarting at the nM range. Surprisingly, embodiments of the presentinvention demonstrate that other fatty acids different fromcis-2-decenoic acid not only work, but at much lower concentrations thancis-2-decenoic acid.

In one embodiment, a method is disclosed for dispersing a biofilm in anaqueous stream by contacting the aqueous stream with a biodispersantcomposition with at least one unsaturated fatty acid (“FA”) which is not2-decenoic acid. Such fatty acids can have a polar head group on aterminal end, and can optionally be used in conjunction with 2-decenoicacid, although other fatty acids are better as explained above. Thepolar head group may include at least one functional group selected fromthe group consisting of a ketone, a carboxylic acid, an amide, aphosphate, an aryl, and a cyclic aliphatic structure. Also, the at leastone FA may include two or more unsaturated fatty acids, such as two orthree or four or five fatty acids.

The at least one FA may have the following chemical formula:

R¹-R⁵—CH₃

wherein R¹ is an aryl, —COR², —COOR², —CONR³R⁴, or —PO₃(R²)₃; R² is H,an alkyl, an aryl or arylalkyl, or a halide; R³ and R⁴ may be the sameor different and are H, a hydroxyl, an alkyl, an aryl or arylalkyl, ahalide, or a sulfo (sulfonic acid group); R⁵ is an aliphatic chainhaving 2-30 carbon atoms and at least one double bond; and wherein whenR¹ is —COOH and R⁵ has eight carbon atoms and the FA has only one doublebond, such double bond is not on the number 2 carbon. In an embodiment,R⁵ is an aliphatic chain having at least two double bonds, such as twoor three double bonds. More particularly, R⁵ has 9-18 carbon atoms. Inan embodiment, the double bonds are present on the carbon 5 to carbon 9positions. For purposes of this disclosure, in the structure R¹-R⁵—CH₃,the CH₃ is the carbon 1 position, and the positions increase as thecarbons get closer to R¹. Also, the FA may not have a double bond on thenumber 2 carbon.

The FA may be equal to or less than about 80% by weight of a totalweight of the biodispersant composition. In another embodiment, the FAmay range from about 20% to about 70% by weight of a total weight of thebiodispersant composition. Alternatively, the FA may range from about30% to about 60% of a total weight of the biodispersant composition.

The fatty acid may be artificially or naturally sourced and can be a cisor trans fatty acid, or a combination of both. The fatty acid may belinear or branched, more particularly linear. Naturally sourced fattyacids may come from animal or plant sources, including, but not limitedto, fish oil, beef fat, krill oil, fowl fat, olive oil, palm oil, canolaoil, soya oil, corn oil and seaweed. Natural sources of fatty acids arerenewable and effective biodispersants with little or no health andsafety concerns. These fatty acids may be considered a biodegradable ora “green” alternative to many dispersants currently used in aqueoussystems. Suitable fatty acids may be unsaturated (such aspolyunsaturated) fatty acids and include, but are not limited to,(Z)-tetradec-9-enoic acid, hexadec-9-enoic acid, (Z)-6-hexadecenoicacid, (9Z,11E,13E)-octadeca-9,11,13-trienoic acid, (9Z)-octadec-9-enoicacid, (E)-octadec-9-enoic acid, (E)-octadec-11-enoic acid,(9Z,12Z)-9,12-octadecadienoic acid, (9E,12E)-octadeca-9,12-dienoic acid,(9Z,12Z,15Z)-9,12,15-octadecatrienoic acid,(5Z,8Z,11Z,14Z)-5,8,11,14-eicosatetraenoic acid,(5Z,8Z,11Z,14Z,17Z)-5,8,11,14,17-icosapentaenoic acid,(Z)-docos-13-enoic acid,(4Z,7Z,10Z,13Z,16Z,19Z)-docosa-4,7,10,13,16,19-hexaenoic acid, andcombinations thereof. In yet another embodiment, the biodispersantcomposition may comprise (9Z,11E,13E)-octadeca-9,11,13-trienoic acid,(5Z,8Z,11Z,14Z,17Z)-5,8,11,14,17-icosapentaenoic acid, and(4Z,7Z,10Z,13Z,16Z,19Z)-docosa-4,7,10,13,16,19-hexaenoic acid.

In yet another embodiment, the biodispersant composition may comprise atleast one saturated or aliphatic fatty acid in addition to theunsaturated fatty acid. Suitable saturated fatty acids include, but arenot limited to, octanoic acid, decanoic acid, dodecanoic acid,tetradecanoic acid, hexadecanoic acid, octadecanoic acid, icosanoicacid, docosanoic acid, tetracosanoic acid, hexacosanoic acid.

In another embodiment, the biodispersant composition may comprise waterand at least one emulsifier. More particularly, the composition containsan emulsion. While the emulsion can be an oil-in-water emulsion, it maybe a water-in-oil emulsion for increased concentration of the fattyacids, which would form the oil phase of the emulsion. The emulsifiersmay act to disperse the FA throughout the biodispersant composition oraqueous stream being treated. The emulsifier may be an effectivebiodispersant by itself, or it may contribute minimally or not at all tothe FA in dispersing the biofilm. Suitable emulsifiers include, but arenot limited to, ethoxylated surfactants, alkyl alcohols, carboxylicacids and their analogues, such as trichlorohexanoic acid, poylamines,such as polyethyleneimine, and combinations thereof. Additionalemulsifier examples include polysiloxanes, carbosilanes, dibromobutane,and dicyanobutane and combinations thereof. In another embodiment, theemulsifier may range from about 0.5% to about 30% by weight of a totalweight of the biodispersant composition, such as 1%-20%, 1%-10%, and5-10%.

An inorganic salt solution may also be added to help stabilize theemulsion and to control pH, and can comprise at least one memberselected from the group consisting of an alkali or alkaline chloride, analkali or alkaline sulfate, or combinations thereof. Suitable inorganicsalt solutions include, but are not limited to, NaCl or MgSO₄ solutions.The inorganic salt solution may range from about 0.1 to about 30% byweight of a total weight of the biodispersant composition, such as0.1-20%, 0.1-10%, and 0.1-1%.

A suitable ethoxylated surfactant may comprise polyethylene glycol(“PEG”) polymers, polyoxyethylene-polyoxypropylene block copolymers(“EO/PO block copolymer”), polyoxyethylene sorbitan monooeleate andcombinations thereof. The ethoxylated surfactant may be used from about5% to about 10% by weight of a total weight of the biodispersantcomposition, although other ranges are envisioned for the emulsifiers,as disclosed above.

In yet another embodiment, the biodispersant composition may comprise atleast one water-soluble pH adjusting agent. The pH adjusting agent mayrange from about 0.1% to about 10% by weight of a total weight of thebiodispersant composition and can include, for example, one or moreinorganic or organic bases, or one or more inorganic or organic acids.The inorganic bases can include one or more of NaOH, NaHCO₃, and NaCO₃.The inorganic acids can include one or more of HCl, H₂SO₄, and H₃PO₄.Organic acids may include one or more of organic sulfonates, organicphosphonates, and organic carboxylic acids. Organic bases can includeone or more of amine based compounds such as methyl amines. Organicspecies can be single molecules or polymers.

The FA may be used in conjunction with a biocide to disperse a biofilmthereby reducing the amount of biocide required to kill the bacteria ina given aqueous system. Accordingly, in another embodiment, thebiodispersant composition may further comprise at least oneantimicrobial composition. The antimicrobial composition may beoxidizing or non-oxidizing biocides. Examples of non-oxidizing biocidesinclude, but are not limited to, guanidine or biguanidine salts,quaternary ammonium salts, phosphonium salts, 2-bromo-2-nitropropane-1,3-diol,5-chloro-2-methyl-4-isothiazolin-3-one/2-methyl-4-isothiazolin-3-one,n-alkyl-dimethylbenzylammonium chloride,2,2,dibromo-3-nitrilopropionamidemethylene-bis(thiocyanate),dodecylguanidine hydrochloride, glutaraldehyde,2-(tert-butylamino)-4-chloro-6-(ethylamino)-s-triazine,beta-bromonitrostyrene, tributyltinoxide, n-tributyltetradecylphosphonium chloride, tetrahydroxymethyl phosphonium chloride,4,5,-dichloro-1,2,-dithiol-3-one, sodium dimethyldithiocarbamate,disodium ethylenebisdithiocarbamate, Bis(trichloromethyl)sulfone,3,5-dimethyl-tetrahydro-2H-1,3,5,-thiadiazine-2-thione,1,2,-benzisothiazolin-3-one, decylthioethylamine hydrochloride andcombinations thereof. Examples of oxidizing biocides include, but arenot limited to, copper sulfate, silver nitrate,bromochlorodimethylhydantoin, sodium bromide, dichlorodimethylhydantoin,sodium hypochlorite, hydrogen peroxide, chlorine dioxide, sodiumchlorite, bromine chloride, peracetic acid and precursors, sodiumtrichloroisocyanurate, sodium trichloroisocyanurate, and combinationsthereof. In yet another embodiment, the antimicrobial composition may bea polyalkylene guanidine or polyalkylene biguanidine salt biocide.

In another method embodiment, the concentration of the biodispersantcomposition relative to the aqueous stream treated may range from about0.1 to about 1000 ppm by volume of the aqueous stream. In yet anotherembodiment, the concentration of the biodispersant composition to theaqueous stream may range from about 10 to about 100 ppm by volume of theaqueous stream. Alternatively, the concentration of the biodispersantcomposition to the aqueous stream may range from about 20 to about 50ppm by volume of the aqueous stream.

In another embodiment, biodispersant compositions are disclosed. Thebiodispersant composition comprises at least one unsaturated fatty acid(“FA”) which is not 2-decenoic acid. The fatty acid may have a polarhead group on a terminal end. The biodispersant composition optionallyalso comprises 2-decenoic acid. The biodispersant composition may alsoinclude water and at least one emulsifier selected from ethoxylatedsurfactants, alkyl alcohols, carboxylic acids, and combinations thereof,and more particularly comprises an emulsion. The polar head group of thefatty acid may include at least one functional group selected from thegroup consisting of a ketone, a carboxylic acid, an amide, a phosphate,an aryl or arylalkyl, and a cyclic aliphatic structure. The least one FAmay include two or more unsaturated fatty acids, such as two or three,or four, or five. The FA may have the following chemical formula:

R¹-R⁵—CH₃

wherein R¹ is an aryl or arylalkyl, —COR², —COOR², or —CONR³R⁴,—PO₃(R²)₃; R² is H, an alkyl, an aryl or arylalkyl, or a halide; R³ andR⁴ may be the same or different and are H, a hydroxyl, an alkyl, an arylor arylalkyl, a halide, or a sulfo (sulfonic acid group); R⁵ is analiphatic chain having 2-30 carbon atoms and at least one double bond;and wherein when R¹ is —COOH and R⁵ has eight carbon atoms and the FAhas only one double bond, such double bond is not on the number 2carbon. In an embodiment, the FA has 9-18 carbon atoms. R⁵ can be analiphatic chain having at least two double bonds, more particularly, twodouble bonds or three double bonds. The double bonds may be on the C5-C9positions. The FA may not have a double bond on the number 2 carbon.

The FA may be equal to or less than about 80% by weight of a totalweight of the biodispersant composition. In another embodiment, the FAmay range from about 20% to about 70% by weight of a total weight of thebiodispersant composition. Alternatively, the FA may range from about30% to about 60% of a total weight of the biodispersant composition.

Suitable fatty acids may be saturated or unsaturated fatty acids andinclude, but are not limited to, (Z)-tetradec-9-enoic acid,hexadec-9-enoic acid, (Z)-6-hexadecenoic acid,(9Z,11E,13E)-octadeca-9,11,13-trienoic acid, (9Z)-octadec-9-enoic acid,(E)-octadec-9-enoic acid, (E)-octadec-11-enoic acid,(9Z,12Z)-9,12-octadecadienoic acid, (9E,12E)-octadeca-9,12-dienoic acid,(9Z,12Z,15Z)-9,12,15-octadecatrienoic acid,(5Z,8Z,11Z,14Z)-5,8,11,14-eicosatetraenoic acid,(5Z,8Z,11Z,14Z,17Z)-5,8,11,14,17-icosapentaenoic acid,(Z)-docos-13-enoic acid,(4Z,7Z,10Z,13Z,16Z,19Z)-docosa-4,7,10,13,16,19-hexaenoic acid, andcombinations thereof. In yet another embodiment, the biodispersantcomposition may comprise (9Z,11E,13E)-octadeca-9,11,13-trienoic acid,(5Z,8Z,11Z,14Z,17Z)-5,8,11,14,17-icosapentaenoic acid, and(4Z,7Z,10Z,13Z,16Z,19Z)-docosa-4,7,10,13,16,19-hexaenoic acid.

In another embodiment, the biodispersant composition may include waterand an emulsion, whether oil-in-water or water-in-oil. In an embodiment,the emulsion may be a water-in-oil emulsion to have a higherconcentration of the FA, which forms the oil phase of the emulsion. Thecomposition may include at least one emulsifier. Suitable emulsifiersinclude, but are not limited to, ethoxylated surfactants, alkylalcohols, carboxylic acids and their analogues, such astrichlorohexanoic acid, poylamines, such as polyethyleneimine, andcombinations thereof. Additional emulsifier examples includepolysiloxanes, carbosilanes, dibromobutane, and dicyanobutane, andcombinations thereof. In another embodiment, the emulsifier may rangefrom about 0.5% to about 30% by weight of a total weight of thebiodispersant composition, such as 1%-20%, 1%-10%, and 5-10%.

An inorganic salt solution may also be included to stabilize theemulsion and control pH, and may comprise at least one member selectedfrom the group consisting of an alkali or alkaline chloride, an alkalior alkaline sulfate, or combinations thereof. Suitable inorganic saltsolutions include, but are not limited to, NaCl or MgSO₄ solutions. Theinorganic salt solution may range from about 0.1 to about 30% by weightof a total weight of the biodispersant composition, such as 0.1-20%,0.1-10%, and 0.1-1%.

A suitable ethoxylated surfactant may comprise polyethylene glycol(“PEG”) polymers, polyoxyethylene-polyoxypropylene block copolymers(“EO/PO block copolymer”), polyoxyethylene sorbitan monooeleate andcombinations thereof.

In yet another embodiment, the biodispersant composition may comprise atleast one water-soluble pH adjusting agent. The pH adjusting agent mayrange from about 0.1% to about 10% by weight of a total weight of thebiodispersant composition.

In another embodiment, the biodispersant composition may comprise atleast one antimicrobial composition. The antimicrobial composition maybe oxidizing or non-oxidizing biocides. Examples of non-oxidizingbiocides include, but are not limited to, guanidine or biguanidinesalts, quaternary ammonium salts, phosphonium salts,2-bromo-2-nitropropane-1, 3-diol,5-chloro-2-methyl-4-isothiazolin-3-one/2-methyl-4-isothiazolin-3-one,n-alkyl-dimethylbenzylammonium chloride,2,2,dibromo-3-nitrilopropionamidemethylene-bis(thiocyanate),dodecylguanidine hydrochloride, glutaraldehyde,2-(tert-butylamino)-4-chloro-6-(ethylamino)-s-triazine,beta-bromonitrostyrene, tributyltinoxide, n-tributyltetradecylphosphonium chloride, tetrahydroxymethyl phosphonium chloride,4,5,-dichloro-1,2,-dithiol-3-one, sodium dimethyldithiocarbamate,disodium ethylenebisdithiocarbamate, Bis(trichloromethyl)sulfone,3,5-dimethyl-tetrahydro-2H-1,3,5,-thiadiazine-2-thione,1,2,-benzisothiazolin-3-one, decylthioethylamine hydrochloride andcombinations thereof. Examples of oxidizing biocides include, but arenot limited to, copper sulfate, silver nitrate,bromochlorodimethylhydantoin, sodium bromide, dichlorodimethylhydantoin,sodium hypochlorite, hydrogen peroxide, chlorine dioxide, sodiumchlorite, bromine chloride, peracetic acid and precursors, sodiumtrichloroisocyanurate, sodium trichloroisocyanurate, and combinationsthereof. In yet another embodiment, the antimicrobial composition may bea polyalkylene guanidine or polyalkylene biguanidine salt biocide, or acombination thereof. In yet another embodiment, the antimicrobialcomposition may range from about 5% to about 10% by weight of a totalweight of the biodispersant composition.

EXAMPLES

To test the efficacy of the fatty acid biodispersant at reducingbiofilm, biofilms were established on 316 SS coupons. First, sterilizedculture containers were prepared. The containers were 1000-ml beakerscharged with a magnetic stirrer and 490 ml of filtered and sterilizedartificial cooling-water (“ACW”). The ACW was prepared to simulate thewater typically found in industrial cooling-water systems. The ACW hadthe composition as in Table 1.

TABLE 1 Component Amount Distilled Water 1.0 l CaCl₂•2H₂O 1.47 gMgSO₄•7H₂O 1.23 g NaHCO₃ 0.637 g Na₂CO₃ 0.133 g NaH₂SO₄•H₂O 0.0116 g

Then, 10 ml of sterilized 30 g/l Tryptic soy broth (“TSB”) was added tothe beakers and mixed with the ACW to form a culture solution. Next, 50ml of culture solution was removed from each beaker. Then 50 ml (50 ppmby volume) of a different biodispersant composition was added to eachbeaker.

Exemplary biodispersant compositions have the general formula as inTable 2. Fish oil was used as the fatty acid source. The fish oilcomprised ≦30.0 wt % of a mixture of palmitic and stearic acids, and20.0-31.0 wt % of an omega-3 fatty acid mixture as triglycerides. Thefatty acid mixture comprised (9Z,11E,13E)-octadeca-9,11,13-trienoicacid, (5Z,8Z,11Z,14Z,17Z)-5,8,11,14,17-icosapentaenoic acid, and(4Z,7Z,10Z,13Z,16Z,19Z)-docosa-4,7,10,13,16,19-hexaenoic acid.

TABLE 2 Component Amount Fish oil (fatty acid source) 30-60 parts byweight polysorbate 80 (emulsifier)  5-10 parts by weight 0.1M NaClsolution (inorganic salt) 30-65 parts by weight Water balance

The different biodispersant compositions tested included an exemplarycomposition (“Ex1”) and multiple comparative compositions (Comps 2-4) aslisted in Table 3. The balance of the compositions listed was water.Comp 1 was a biodispersant composition comprising polyethylenimine(“PEI”). Comp 2 and Comp 3 were biodispersant compositions comprisingethoxylated anionic surfactants composed of alkyl substitutedcarboxylated acid or salt thereof and an EO/PO block copolymer asdescribed in U.S. Pat. No. 6,514,458. Comp 2 comprised straight chainalkyl substituted carboxylated acid. Comp 3 comprise a branched alkylsubstituted carboxylated acid. Comp 4 also comprised an ethoxylatedanionic surfactants composed of alkyl substituted carboxylated acid orsalt thereof and an EO/PO block copolymer. Comp 5 (not shown) was alsotested. Comp 5 was similar to Ex1, but DI water was used in place of thefish oil. Comp 5 was not effective at removing biofilm.

TABLE 3 Composition Component Amount Ex1 fish oil (fatty acid source) 60wt % polysorbate 80 10 wt % 0.1M NaCl solution 25 wt % 5N NaOH 5 wt %Comp1 polyethyleneimine 50 wt % Comp2 alkyl (straight chain) 35 wt %substituted carboxylated acid salt EO/PO block copolymer 12.6 wt % Comp3alkyl (branched chain) 35 wt % substituted carboxylated acid salt EO/POblock copolymer 12.6 wt % Comp4 alkyl substituted carboxylated 30-50 wt% acid (potassium) salt EO/PO block copolymer 5-20 wt %

After adding one of the biodispersant compositions listed above to eachbeaker, (50 ml; 50 ppm by volume), coupon holders for each beaker wereprepared for suspending the coupons vertically in the culture solution.Each coupon holder comprised a beaker lid with a means for attaching 3rods from which the SS coupons could be attached and suspended in theculture test solution. The rods' length was chosen such that when thecoupons were attached, they were fully immersed in the culture solutionat an equal depth without touching the bottom of the beaker. The couponswere then aseptically suspended in the beakers and the lids weresecured.

The beakers were then gently stirred for 24 hours at the same rotationsper minute (rpm). After 24 hours, the coupons were removed and dipped inDI water to remove any unattached bacteria. The coupons were thenremoved from the rods and each coupon was placed into a 50-ml sterilepolypropylene centrifuge tube containing 35 ml of sterile phosphatebuffered saline (pH=7.2-7.6). Each tube was then placed in a centrifugeand vortexed on high for 1 minute. The samples were then enumeratedusing Petrifilm™ counts. The films were incubated at 30° C. for aminimum of 48 hours before the Colony Forming Units/ml (CFU/ml) werecounted. The average CFU/ml/cm² was calculated for each composition bytaking the CFU/ml for each coupon, dividing the CFU by the area of thecoupon (8.77 cm²), and averaging the results. The % Reduction was thencalculated as in equation 1.

$\begin{matrix}{{\% \mspace{14mu} {Reduction}} = {\frac{\left( {{{AveControl}\left( {\frac{CFU}{ml}\text{/}{cm}^{2}} \right)} - {{AveBDC}\left( {\frac{CFU}{ml}\text{/}{cm}^{2}} \right)}} \right)}{{AveControl}\left( {\frac{CFU}{ml}\text{/}{cm}^{2}} \right)} \times 100}} & (1)\end{matrix}$

wherein “AveControl” is the average CFU/ml/cm² of the control and“AveBDC” is the average CFU/ml/cm² for each biodispersant composition(“BDC”). The % Reduction for the biodispersant compositions are shown inFIG. 1.

The effectiveness of Ex1 was also tested at various concentrations in aseparate set of experiments performed using the same procedure as listedabove. The % Reduction of Ex1 at various concentrations is shown in FIG.2. The data with a “*” are presumed outliers, but have been included inthe interest of full disclosure.

The foaming characteristics of the biodispersant compositions listed inTable 3 were also tested. To conduct the foam tests, 50 ppm of theappropriate biodispersant composition was mix with DI water in 500 mLflask to form a test solution. Then, 200 mL of the test solution waspoured into a 500 mL graduated cylinder. The cylinder was capped andshaken in an up and down motion for ten seconds (approximately 40times). The volume of the solution and any foam therein was thenmeasured at 0, 0.5, 1, 2, and 3 minutes. The results of the foam testare listed in Table 4.

TABLE 4 Time Comp3 (min) Comp1 Comp2 Comp3 repeat Comp4 Ex1 0 200 275275 250 280 210 0.5 200 205 260 225 270 210 1 200 200 250 220 270 210 2200 200 240 220 265 210 3 200 200 230 220 260 210

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they have structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

1. A method of dispersing a biofilm in an aqueous stream by contactingsaid aqueous stream with a biodispersant composition containing at leastone unsaturated fatty acid (“FA”) which is not 2-decenoic acid, said FAcomprising a fatty acid having a polar head group on a terminal end,wherein the biodispersant composition optionally also comprises2-decenoic acid.
 2. The method according to claim 1, wherein the polarhead group comprises at least one functional group selected from thegroup consisting of a ketone, a carboxylic acid, an amide, a phosphate,an aryl or arylalkyl, and a cyclic aliphatic structure.
 3. The methodaccording to claim 1, wherein the at least one FA comprises two or moreunsaturated fatty acids.
 4. The method according to claim 1, wherein theat least one FA comprises the following chemical formula:R¹-R⁵—CH₃ wherein R¹ is an aryl or arylalkyl, —COR², —COOR², —CONR³R⁴,or —PO₃(R²)₃; R² is H, an alkyl, an aryl or arylalkyl, or a halide; R³and R⁴ may be the same or different and are H, a hydroxyl, an alkyl, anaryl or arylalkyl, a halide, or a sulfo (sulfonic acid group); R⁵ is analiphatic chain having 2-30 carbon atoms and at least one double bond;and wherein when R¹ is —COOH and R⁵ has eight carbon atoms and the FAhas only one double bond, such double bond is not on the number 2carbon.
 5. The method according to claim 4, wherein R⁵ is an aliphaticchain having at least two double bonds.
 6. The method of claim 1,wherein the at least one FA is 1-80% by weight of a total weight of saidbiodispersant composition.
 7. The method of claim 1, wherein the atleast one FA is selected from the group consisting of(Z)-tetradec-9-enoic acid, hexadec-9-enoic acid, (Z)-6-hexadecenoicacid, (9Z,11E,13E)-octadeca-9,11,13-trienoic acid, (9Z)-octadec-9-enoicacid, (E)-octadec-9-enoic acid, (E)-octadec-11-enoic acid,(9Z,12Z)-9,12-octadecadienoic acid, (9E,12E)-octadeca-9,12-dienoic acid,(9Z,12Z,15Z)-9,12,15-octadecatrienoic acid,(5Z,8Z,11Z,14Z)-5,8,11,14-eicosatetraenoic acid,(5Z,8Z,11Z,14Z,17Z)-5,8,11,14,17-icosapentaenoic acid,(Z)-docos-13-enoic acid,(4Z,7Z,10Z,13Z,16Z,19Z)-docosa-4,7,10,13,16,19-hexaenoic acid, andcombinations thereof.
 8. The method of claim 7, wherein said FAcomprises (9Z,11E,13E)-octadeca-9,11,13-trienoic acid,(5Z,8Z,11Z,14Z,17Z)-5,8,11,14,17-icosapentaenoic acid, and/or(4Z,7Z,10Z,13Z,16Z,19Z)-docosa-4,7,10,13,16,19-hexaenoic acid.
 9. Themethod of claim 1, wherein said biodispersant composition furthercomprises water and at least one emulsifier selected from ethoxylatedsurfactants, alkyl alcohols, carboxylic acids, and combinations thereof,and wherein the biodispersant composition comprises an emulsion.
 10. Themethod of claim 9, wherein the biodispersant composition furthercomprises an inorganic salt solution which includes at least one memberselected from the group consisting of an alkali or alkaline chloride, analkali or alkaline sulfate, or combinations thereof, and wherein saidethoxylated surfactant comprises at least one selected from the groupconsisting of a polyethylene glycol polymer, apolyoxyethylene-polyoxypropylene block copolymer, polyoxyethylenesorbitan monooeleate and combinations thereof.
 11. The method of claim1, wherein a concentration of said biodispersant composition relative tosaid aqueous stream ranges from about 0.1 to about 1000 ppm by volume ofsaid aqueous stream.
 12. The method of claim 1, wherein saidbiodispersant composition further comprises at least one antimicrobialcomposition selected from the group consisting of guanidine orbiguanidine salts, quaternary ammonium salts, phosphonium salts,2-bromo-2-nitropropane-1, 3-diol,5-chloro-2-methyl-4-isothiazolin-3-one/2-methyl-4-isothiazolin-3-one,n-alkyl-dimethylbenzylammonium chloride,2,2,dibromo-3-nitrilopropionamidemethylene-bis(thiocyanate),dodecylguanidine hydrochloride, glutaraldehyde,2-(tert-butylamino)-4-chloro-6-(ethylamino)-s-triazine,beta-bromonitrostyrene, tributyltinoxide, n-tributyltetradecylphosphonium chloride, tetrahydroxymethyl phosphonium chloride,4,5,-dichloro-1,2,-dithiol-3-one, sodium dimethyldithiocarbamate,disodium ethylenebisdithiocarbamate, Bis(trichloromethyl)sulfone,3,5-dimethyl-tetrahydro-2H-1,3,5,-thiadiazine-2-thione,1,2,-benzisothiazolin-3-one, decylthioethylamine hydrochloride, coppersulfate, silver nitrate, bromochlorodimethylhydantoin, sodium bromide,dichlorodimethylhydantoin, sodium hypochlorite, hydrogen peroxide,chlorine dioxide, sodium chlorite, bromine chloride, peracetic acid andprecursors, sodium trichloroisocyanurate, sodium trichloroisocyanurate,trichlorohexanoic acid, and combinations thereof.
 13. A biodispersantcomposition comprising at least one unsaturated fatty acid (“FA”) whichis not 2-decenoic acid, said FA having a polar head group on a terminalend, wherein the biodispersant composition optionally also comprises2-decenoic acid, and wherein the biodispersant composition furthercomprises water and at least one emulsifier selected from ethoxylatedsurfactants, alkyl alcohols, carboxylic acids, and combinations thereof,and wherein the biodispersant composition comprises an emulsion.
 14. Thebiodispersant composition of claim 13, wherein the polar head groupcomprises at least one functional group selected from the groupconsisting of a ketone, a carboxylic acid, an amide, a phosphate, anaryl or arylalkyl, and a cyclic aliphatic structure.
 15. Thebiodispersant composition of claim 13, wherein the at least one FAcomprises two or more unsaturated fatty acids.
 16. The biodispersantcomposition according to claim 13, wherein the at least one FA comprisesthe following chemical formula:R¹-R⁵—CH₃ wherein R¹ is an aryl or arylalkyl, —COR², —COOR², —CONR³R⁴,or —PO₃(R²)₃; R² is H, an alkyl, an aryl or arylalkyl, or a halide; R³and R⁴ may be the same or different and are H, a hydroxyl, an alkyl, anaryl or arylalkyl, a halide, or a sulfo (sulfonic acid group); R⁵ is analiphatic chain having 2-30 carbon atoms and at least one double bond;and wherein when R¹ is —COOH and R⁵ has eight carbon atoms and the FAhas only one double bond, such double bond is not on the number 2carbon.
 17. The biodispersant composition of claim 16, wherein R⁵ is analiphatic chain having at least two double bonds.
 18. The biodispersantcomposition of claim 13, wherein said FA is 1-80% by weight of a totalweight of said biodispersant composition.
 19. The biodispersantcomposition of claim 13, wherein at least one FA is selected from thegroup consisting of (Z)-tetradec-9-enoic acid, hexadec-9-enoic acid,(Z)-6-hexadecenoic acid, (9Z,11E,13E)-octadeca-9,11,13-trienoic acid,(9Z)-octadec-9-enoic acid, (E)-octadec-9-enoic acid,(E)-octadec-11-enoic acid, (9Z,12Z)-9,12-octadecadienoic acid,(9E,12E)-octadeca-9,12-dienoic acid,(9Z,12Z,15Z)-9,12,15-octadecatrienoic acid,(5Z,8Z,11Z,14Z)-5,8,11,14-eicosatetraenoic acid,(5Z,8Z,11Z,14Z,17Z)-5,8,11,14,17-icosapentaenoic acid,(Z)-docos-13-enoic acid,(4Z,7Z,10Z,13Z,16Z,19Z)-docosa-4,7,10,13,16,19-hexaenoic acid, andcombinations thereof.
 20. The biodispersant composition of claim 13,wherein said FA comprises (9Z,11E,13E)-octadeca-9,11,13-trienoic acid,(5Z,8Z,11Z,14Z,17Z)-5,8,11,14,17-icosapentaenoic acid, and/or(4Z,7Z,10Z,13Z,16Z,19Z)-docosa-4,7,10,13,16,19-hexaenoic acid.
 21. Thebiodispersant composition of claim 13, further comprising an inorganicsalt solution including at least one member selected from the groupconsisting of an alkali or alkaline chloride, an alkali or alkalinesulfate, or combinations thereof, and wherein said ethoxylatedsurfactant comprises at least one selected from the group consisting ofa polyethylene glycol polymer, a polyoxyethylene-polyoxypropylene blockcopolymer, polyoxyethylene sorbitan monooeleate and combinationsthereof.
 22. The biodispersant composition of claim 13, wherein saidbiodispersant composition further comprises at least one antimicrobialcomposition selected from the group consisting of guanidine orbiguanidine salts, quaternary ammonium salts, phosphonium salts,2-bromo-2-nitropropane-1, 3-diol,5-chloro-2-methyl-4-isothiazolin-3-one/2-methyl-4-isothiazolin-3-one,n-alkyl-dimethylbenzylammonium chloride,2,2,dibromo-3-nitrilopropionamidemethylene-bis(thiocyanate),dodecylguanidine hydrochloride, glutaraldehyde,2-(tert-butylamino)-4-chloro-6-(ethylamino)-s-triazine,beta-bromonitrostyrene, tributyltinoxide, n-tributyltetradecylphosphonium chloride, tetrahydroxymethyl phosphonium chloride,4,5,-dichloro-1,2,-dithiol-3-one, sodium dimethyldithiocarbamate,disodium ethylenebisdithiocarbamate, Bis(trichloromethyl)sulfone,3,5-dimethyl-tetrahydro-2H-1,3,5,-thiadiazine-2-thione,1,2,-benzisothiazolin-3-one, decylthioethylamine hydrochloride, coppersulfate, silver nitrate, bromochlorodimethylhydantoin, sodium bromide,dichlorodimethylhydantoin, sodium hypochlorite, hydrogen peroxide,chlorine dioxide, sodium chlorite, bromine chloride, peracetic acid andprecursors, sodium trichloroisocyanurate, sodium trichloroisocyanurate,trichlorohexanoic acid, and combinations thereof.